"Putting legislation through for offshore processing on Nauru and Manus Island was a step in the right direction," he said.

But the Government says there is considerable work needed at the centre on Nauru despite the Coalition's claim that it was ready to go.

Two teams have been sent to Nauru and Manus Island to check what work needs to be done before the detention centres are ready to accommodate asylum seekers from Christmas Island.

Defence Minister Stephen Smith says the Government will have the report into the state of the detention facilities early this week.

When the do centres open, there will be 1,500 places for asylum seekers at Nauru and 600 places at Manus Island.

Yet this week alone, more than 500 asylum seekers arrived in Australia by boat.

'Punishing' policy

Meanwhile Navi Pillay, the United Nations High Commissioner for Human Rights, has warned that some aspects of the policy could risk the human rights of migrants and refugees.

The Greens share similar concerns.

Greens senator Sarah Hanson-Young says the Government has only implemented the "nastiest" and "most punishing" of the recommendations handed down by a three-man expert panel.

"We know that detaining people indefinitely with no limits in a very remote island, in an island prison, costs peoples' lives," she told Insiders.

"And it drives very, very brave, courageous, intelligent people to be madmen and be insane. Pushing them to the point of self destruction.

"People are saying, well, unless we put those guaranteed protections in place ... those protections for people to access proper mental health services, [and] we have a time limit on the length of time people are detained, then none of this is going to be any better than it was last time."